Paper-corrugating machine



March 17, 1931.

c. J. SCHOO PAPER CORRUGATING MACHINE Filed Aug. 29 1930 JNVENTOR.CLARfA/CE J 567/00 ATTORNEYS.

Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE CLARENCE J'. SCHOO,OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL FIBRE 4 BOX (30., OFWEST SPRINGFIELD, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTSPAPER-CORRUGATING MACHINE Application filed August 29, 1930. Serial No.478,615.

This invention relates to improvements in machines for the manufactureof corrugated paper board. The procedure generally followed in theproduction of this material is 5 to pass a web of suitable heavy paperbetween a pair of meshing fluted rollers and then to secure adhesively aweb of paper to each side of the corrugated sheet. These external orlining sheets are bridged across the corrugations in the central web andhold the latter against. subsequent collapse.

ln passing between the corrugating rolls the paper is subjected to heavystress Depending upon the nature of the paper 1t may yield to the stresswith resulting weakening of its fibers, or it ma resist the stress to apointwhere corrugatlons of full depth will not be obtained. I have foundthat by applying to the corrugating rolls a thin film of melted paraflinor other lubricant the culty of forming full height corrugatlons withoutinjurious strain disappears. It 15 the object of the present inventionto provide a corrugating mechanism with mechanism for transferring tothe corrugating rolls a film of molten parafiin or other lubricant ofcontrollable amount. The quantity applied is pref erably suflicientlysmall so that the amount transferred to the paper by its contact withthe roll will be insufficient to produce any commercially perceptibleeffect on the original properties of the paper, although suflicient toproduce corrugations of full height without injurious strain on thefibers. A further object is to provide a mechamsm of this characterwhich can use molten parafiin as a lubricant without the necessity ofusing complicated steam jacketing. A further object is to provide amechanism of this general character which will apply the lubricant Insuch a manner that it will not injuriously afiect the bonding to thecorrugated sheet of the subsequent applied adhesively coated liningsheets. dditional objects will appear from the following description andclaims.

The invention will now be described with particular reference to theaccompanying drawingwl1ich is a diagrammatic representation of mechanismby which my improved process may be practiced. The web a of material tobe corrugated passes over guide rolls 10 and a steaming device 11 to thesurface of a corrugating roll 12. This roll has teeth 13 meshing withsimilar teeth 14 on a second corrugating roll 15. The roll 12 is mountedon a bracket 16 pivoted at 17 to a stationary part of the machine and ispressed towards the roll 15 by a compression spring 18. As the paper webpasses between the two corrugating rolls, it is forced into its finalcorrugated condition, and is set in this condition by the heat of therolls, generally kept at over 300 F. This heat is generally supplied bysteam circulated through the hollow interior of the rolls. An adhesiveapplying roll 19 runs in contact with the corrugated paper on roll 15and applies a film of adhesive such as sodium silicate to the highpoints of the corrugations. This roll receives adhesive from a supplyroll 20 dipping into a tank 21. A lining web I) is passed over a roll 22running adjacent to the surface of roll 15, and is pressed thereby intoadhering contact with the corrugated paper. The composite web thenpasses an adhesive applying roll 23, which receives adhesive from a roll24 and a tank 25 and applies adhesive to the second side of thecorrugated web. The second lining sheet a is passed around a roll 26 andis pressed against the corrugated web by this roll and a mating roll 27.

This arrangement of apparatus has been described rather briefly, as itis common in the art. It does, however, illustrate the environment withwhich the mechanism now to be described is combined to produce the novelresults referred to above. According to my invention the lubricant ispreferably applied to the crests only of the fiutings on the corrugatingrolls, being allowed to spread over the remainder of the roll surface.This spreading takes place with considerable rapidity on account of theheat of the rolls, and I have found this method of application to haveseveral features of advantage. In the first place the portions of theroll flutings which require the maximum lubrication are the crest andthe sides. It is the crest which receives the maximum frictional contactof the paper during the drawing of the paper around the roll intocorrugated form. It is the sides to which maximum pressure is appliedduring the actual corrugating, and to which the paper is most likely tostick. The bottom of the groove gives comparatively little troubleduring the corrugating operation, and requires little if any lubication.The bottom of the roll flutings, moreover, corresponds to the crest ofthe corrugation which is formed in the paper, and it is to this pointthat the adhesive is subsequently applied. Any appreciable quantity oflubricant will harmfully affect the sticking of the adhesive to thepaper, and it is thus of importance to prevent the accumulation of anexcess of lubricant at the bottoms of the roll flutings. My preferredmanner of applying lubricant to the roll surface consists in permittingthe outer portions of the flutings to wipe against a wick saturated withthe lubricant. This has certain advantages over other methods ofapplication such for example as spraying, for in the latter case theforce of the spray would tend to cause an accumulation of lubricant atthe bottom of the flutings with a minimum at the top and sides, thereverse of the condition desired.

Referring now to the mechanical details of the apparatus which forms thepreferred embodiment of my invention, a tube 80, closed at its ends, islocated adjacent the roll 12. Flanges 31 are secured in parallelrelation along this roll, leaving between them a space communicatingwith the interior of the tube. A wick 32 fills this space and is subjectto comprehension to any degree desired by one or more adjusting screws.By tightening the screws the wick will be compressed and the amount oflubricant delivered from the interior ofthe tube 30 will be lessened.The tube is positioned close to the roll 13, conveniently between it andthe steaming device 11, so that when paraifin is used as a lubricant thenormal heat of the surrounding parts will be suflicient to preserve theparaflin in molten condition without the use of special means forheating the tube. The wick 32 is positioned so that it drags upon theperiphery of the corrugated roll 12, spreading a thin layer of thelubricant upon the crest of the flutings. As the tube is limited in sizeon account of its position and is for the same reason rather diflicultto fill with lubricant, it is preferably kept filled from an externalsource. For this purpose it is conneced by a flexible conduit 34 to asteam jacketed tank 35 which may be positioned wherever convenient.

Above the second corrugating roll 15 is a funnel-shaped trough 36 havinga wick 37 clamped between its lower edges by one or more adjustingscrews 38. This trough is also so located relative to the normallyheated machine parts that in practice parafiin will be kept melted in itdue to the heat of the corrugating rolls, and a separate steam jacketwill be unnecessary. The wick 37 drags over the crests of the fluttingson the roll 15 in the same manner as has been described with relation tothe wick 32.

It will be noted that the wick 32 applies its lubricant to the crests ofthe flutings on roll 13 prior to the contact of the web a with it. Theweb travels at a speed higher than the surface speed of the roll, onaccount of the surplus material required for the formation of thecorrugations. The lubrication greatly decreases the frictionalresistance necessary to be overcome in drawing to the corrugating pointthe amount of paper required. It also facilitates the actual corrugatingoperation and prevents sticking of the paper to the roll. The valleys ofthe flutings on roll 12, which preferably receive the lubricant onlythrough spreading and not directly from the wick, and which thereforereceive the minimum amount, correspond to the crests of the corrugationswhich later contact with the adhesiveapplying roll 19 and with thelining sheet 6. lVhile the total amount of lubricant applied ispreferably very small (about one pound of paraflin for seventeenthousand square feet of paper being enough) this gives added insurancethat on the crests of the corrugations there will not be a quantity oflubricant sufficient to prevent the later applied adhesive fromadhering. Similar remarks of course apply to the wick 37 lVhat I claimis:

1. A paper corrugating machine comprising a pair of mating corrugatingrolls, means for supplying a web of paper between the rolls, and adevice for applying a film of lubricant continuously to the surface ofat least one of the rolls prior to the contact of the paper therewith.

2. A paper corrugating machine comprising a pair of mating flutedcorrugating rolls, a wick located in rubbing contact with the crests ofthe flutings of at least one of said rolls, and means for supplying alubricant to the wick. v t

3. A paper corrugating machine comprising a pair of mating flutedcorrugating rolls, means for supplying a web of paper between the rolls,and a device for applying lubricant continuously to the crests only ofthe flutings of at least one of said rolls.

LA paper corrugating machine comprising a pair of mating heatedcorrugating rollers, a wick located adjacent each of the rollers so asto be in rubbing contact therewith, and a supply of molten parafiinassociated with each wick so as to maintain them saturated with themolten paraffin, said supplies being located in such close adjacency tothe heated rolls as to receive from them a suflicient quantity of heatto retain the paraflin in them in molten condition.

5. A paper corrugating machine comprising a pair of heated matingcorrugating rolls positioned one beside the other, means for supplying aweb of paper across the top of one roll and then between the two rolls,a

steaming device spaced from the roll first contacted with by the paperweb and positioned to deliver steam against the under side of the paperweb, a paraffin reservoir located between the steaming device and theadjacent roll and extending the length of the latter and positioned toreceive heat from both the steaming device and the roll, a wickextending from said reservoir into rubbing contact with the adjacentcorrugated roll, a

second parafiin reservoir located above the second corrugated roll andpositioned so as to receive heat therefrom, and a wick extending fromsaid reservoir into rubbing contact with said second corrugated roll.

6. A machine for making corrugated board a V which comprises a pair ofmating fluted corrugated rolls, means for supplying a web of paperbetween said rolls, a lubricant saturated wick located in rubbingcontact with the crests only of the flutings in each roll to applylubricant to each roll prior to the contact of the paper therewith,means for applying adhesive to the crest only of the corrugations in theweb after the latter has passed between the rolls, and means forapplying a lining sheet to each side of the web in bridging relation tothe adhesive-coated crests of the corrugations therein.

In testimony whereof I have aflixed my signature.

CLARENCE J. SCHOO.

